1. Field of Invention
Aspects of the invention relate to a semiconductor device formed on a SOI (Silicon On Insulator) substrate or on a bulk substrate and a semiconductor memory using the semiconductor device.
2. Description of Related Art
As a shape of the gate on related field of transistors, in addition to the I-type gate used for bulk substrates, the T-type gate used for obtaining the body contact in the SOI substrates can be used. I-type gates are advantageous in that they have small gate capacitance and that they require the minimum sell areas. However, I-type gates are not effective for obtaining the body contact in SOI substrates. In this respect, the T-type gates are effective for separating the source/drain regions from the body contact regions even if the surfaces of field regions in SOI substrates are formed of silicide layers. However, there is a disadvantage that the width of the gate channels of transistors cannot be made constant if the mask shift occurs. Further, it has not been studied to ease the soft error problems caused by such as α lays, γ lays, or neutrons by modifying the shape of gates.